/*
 * Date picker plugin for jQuery
 * http://kelvinluck.com/assets/jquery/datePicker
 *
 * Copyright (c) 2006 Kelvin Luck (kelvinluck.com)
 * Licensed under the MIT License:
 * http://www.opensource.org/licenses/mit-license.php
 *
 * $LastChangedDate: 2007-04-12 10:01:01 +0100 (Thu, 12 Apr 2007) $
 * $Rev: 1672 $
 */

jQuery.datePicker = function()
{
    // so that firebug console.log statements don't break IE
    if (window.console == undefined) { window.console = {log:function(){}}; }

    var months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
    var days = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
    var navLinks = {p:'Prev', n:'Next', c:'Close', b:'Choose date'};
    var dateFormat = 'dmy';
    var dateSeparator = "/";
    var _drawingMonth = false;
    var _firstDayOfWeek;
    var _firstDate;
    var _lastDate;

    var _selectedDate;
    var _openCal;

    var _zeroPad = function(num) {
        var s = '0'+num;
        return s.substring(s.length-2)
        //return ('0'+num).substring(-2); // doesn't work on IE :(
    };
    var _strToDate = function(dIn)
    {
        switch (dateFormat) {
            case 'ymd':
                dParts = dIn.split(dateSeparator);
                return new Date(dParts[0], Number(dParts[1])-1, dParts[2]);
            case 'dmy':
                dParts = dIn.split(dateSeparator);
                return new Date(dParts[2], Number(dParts[1])-1, Number(dParts[0]));
            case 'dmmy':
                dParts = dIn.split(dateSeparator);
                for (var m=0; m<12; m++) {
                    if (dParts[1].toLowerCase() == months[m].substr(0,3).toLowerCase())  {
                        return new Date(Number(dParts[2]), m, Number(dParts[0]));
                    }
                }
                return undefined;
            case 'mdy':
            default:
                var parts = parts ? parts : [2, 1, 0];
                dParts = dIn.split(dateSeparator);
                return new Date(dParts[2], Number(dParts[0])-1, Number(dParts[1]));
        }
    };
    var _dateToStr = function(d)
    {
        var dY = d.getFullYear();
        var dM = _zeroPad(d.getMonth()+1);
        var dD = _zeroPad(d.getDate());
        switch (dateFormat) {
            case 'ymd':
                return dY + dateSeparator + dM + dateSeparator + dD;
            case 'dmy':
                return dD + dateSeparator + dM + dateSeparator + dY;
            case 'dmmy':
                return dD + dateSeparator + months[d.getMonth()].substr(0,3) + dateSeparator + dY;
            case 'mdy':
            default:
                return dM + dateSeparator + dD + dateSeparator + dY;
        }
    };

    var _getCalendarDiv = function(dIn)
    {
        var today = new Date();
        if (dIn == undefined) {
            // start from this month.
            d = new Date(today.getFullYear(), today.getMonth(), 1);
        } else {
            // start from the passed in date
            d = dIn;
            d.setDate(1);
        }
        // check that date is within allowed limits:
        if ((d.getMonth() < _firstDate.getMonth() && d.getFullYear() == _firstDate.getFullYear()) || d.getFullYear() < _firstDate.getFullYear()) {
            d = new Date(_firstDate.getFullYear(), _firstDate.getMonth(), 1);;
        } else if ((d.getMonth() > _lastDate.getMonth() && d.getFullYear() == _lastDate.getFullYear()) || d.getFullYear() > _lastDate.getFullYear()) {
            d = new Date(_lastDate.getFullYear(), _lastDate.getMonth(), 1);;
        }

        var jCalDiv = jQuery("<div></div>").attr('class','popup-calendar');
        var firstMonth = true;
        var firstDate = _firstDate.getDate();

        // create prev and next links
        var prevLinkDiv = '';
        if (!(d.getMonth() == _firstDate.getMonth() && d.getFullYear() == _firstDate.getFullYear())) {
            // not in first display month so show a previous link
            firstMonth = false;
            var lastMonth = d.getMonth() == 0 ? new Date(d.getFullYear()-1, 11, 1) : new Date(d.getFullYear(), d.getMonth()-1, 1);
            var prevLink = jQuery("<a></a>").attr('href', 'javascript:;').html(navLinks.p).click(function()
            {
                jQuery.datePicker.changeMonth(lastMonth, this);
                return false;
            });
            prevLinkDiv = jQuery("<div></div>").attr('class','link-prev').html('&lt;').append(prevLink);
        }

        var finalMonth = true;
        var lastDate = _lastDate.getDate();
        nextLinkDiv = '';
        if (!(d.getMonth() == _lastDate.getMonth() && d.getFullYear() == _lastDate.getFullYear())) {
            // in the last month - no next link
            finalMonth = false;
            var nextMonth = new Date(d.getFullYear(), d.getMonth()+1, 1);
            var nextLink = jQuery("<a></a>").attr('href', 'javascript:;').html(navLinks.n).click(function()
            {
                jQuery.datePicker.changeMonth(nextMonth, this);
                return false;
            });
            nextLinkDiv = jQuery("<div></div>").attr('class','link-next').html('&gt;').prepend(nextLink);
        }

        var closeLink = jQuery("<a></a>").attr('href','javascript:;').html(navLinks.c).click(function()
        {
            jQuery.datePicker.closeCalendar();
        });

        jCalDiv.append(
            jQuery("<div></div>").attr('class', 'link-close').append(closeLink),
            jQuery("<h3></h3>").html(months[d.getMonth()] + ' ' + d.getFullYear())
        ).append(prevLinkDiv).append(nextLinkDiv).append("<br/>");
        var headRow = jQuery("<tr></tr>");
        for (var i=_firstDayOfWeek; i<_firstDayOfWeek+7; i++) {
            var weekday = i%7;
            var day = days[weekday];
            headRow.append(
                jQuery("<th></th>").attr({'scope':'col', 'abbr':day, 'title':day, 'class':(weekday == 0 || weekday == 6 ? 'weekend' : 'weekday')}).html(day.substr(0, 1))
            );
        }

        var tBody = jQuery("<tbody></tbody>");

        var lastDay = (new Date(d.getFullYear(), d.getMonth()+1, 0)).getDate();
        var curDay = _firstDayOfWeek - d.getDay();
        if (curDay > 0) curDay -= 7;

        var todayDate = (new Date()).getDate();
        var thisMonth = d.getMonth() == today.getMonth() && d.getFullYear() == today.getFullYear();

        var w = 0;
        while (w++<6) {
            var thisRow = jQuery("<tr></tr>");
            for (var i=0; i<7; i++) {
                var weekday = (_firstDayOfWeek + i) % 7;
                var atts = {'class':(weekday == 0 || weekday == 6 ? 'weekend ' : 'weekday ')};

                if (curDay < 0 || curDay >= lastDay) {
                    dayStr = ' ';
                } else if (firstMonth && curDay < firstDate-1) {
                    dayStr = curDay+1;
                    atts['class'] += 'inactive';
                } else if (finalMonth && curDay > lastDate-1) {
                    dayStr = curDay+1;
                    atts['class'] += 'inactive';
                } else {
                    d.setDate(curDay+1);
                    var dStr = _dateToStr(d);
                    dayStr = jQuery("<a></a>").attr({'href':'javascript:;', 'rel':dStr}).html(curDay+1).click(function(e)
                    {
                        jQuery.datePicker.selectDate(jQuery.attr(this, 'rel'), this);
                        return false;
                    })[0];
                    if (_selectedDate && _selectedDate==dStr) {
                        jQuery(dayStr).attr('class','selected');
                    }
                }

                if (thisMonth && curDay+1 == todayDate) {
                    atts['class'] += 'today';
                }
                thisRow.append(jQuery("<td></td>").attr(atts).append(dayStr));
                curDay++;
            }
            tBody.append(thisRow);
        }

        jCalDiv.append(
            jQuery("<table></table>").attr('cellspacing',2).append("<thead></thead>")
            .find("thead").append(headRow).parent().append(tBody.children())
        );
        
        if (jQuery.browser.msie) {

            // we put a styled iframe behind the calendar so HTML SELECT elements don't show through
            var iframe = [    '<iframe class="bgiframe" tabindex="-1" src="blank.html" ',
                             'style="display:block; position:absolute;',
                            'top: 0;',
                            'left:0;',
                            'z-index:-1; filter:Alpha(Opacity=\'0\');',
                            'width:3000px;',
                            'height:3000px"/>'].join('');
            jCalDiv.append(document.createElement(iframe));
        }
        
        jCalDiv.css({'display':'block'});
        return jCalDiv[0];
    };
    var _draw = function(c)
    {
        // explicitly empty the calendar before removing it to reduce the (MASSIVE!) memory leak in IE
        // still not perfect but a lot better!
        // Strangely if you chain the methods it reacts differently - when chained opening the calendar on
        // IE uses a bunch of memory and pressing next/prev doubles this memory. When you close the calendar
        // the memory is freed. If they aren't chained then pressing next or previous doesn't double the used
        // memory so only one chunk of memory is used when you open the calendar (which is also freed when you
        // close the calendar).
        jQuery('div.popup-calendar a', _openCal[0]).unbind();
        jQuery('div.popup-calendar', _openCal[0]).empty();
        jQuery('div.popup-calendar', _openCal[0]).remove();
        _openCal.append(c);
    };
    var _closeDatePicker = function()
    {
        jQuery('div.popup-calendar a', _openCal).unbind();
        jQuery('div.popup-calendar', _openCal).empty();
        jQuery('div.popup-calendar', _openCal).css({'display':'none'});

        /*
        if (jQuery.browser.msie) {
            _openCal.unbind('keypress', _handleKeys);
        } else {
            jQuery(window).unbind('keypress', _handleKeys);
        }
        */
        jQuery(document).unbind('mousedown', _checkMouse);
        delete _openCal;
        _openCal = null;
    };
    var _handleKeys = function(e)
    {
        var key = e.keyCode ? e.keyCode : (e.which ? e.which: 0);
        //console.log('KEY!! ' + key);
        if (key == 27) {
            _closeDatePicker();
        }
        return false;
    };
    var _checkMouse = function(e)
    {
        if (!_drawingMonth) {
            var target = jQuery.browser.msie ? window.event.srcElement : e.target;
            //console.log(jQuery(target));
            var cp = jQuery(target).findClosestParent('div.popup-calendar-wrapper');
            if (cp.get(0).className != 'date-picker-holder') {
                _closeDatePicker();
            }
        }
    };

    return {
        getChooseDateStr: function()
        {
            return navLinks.b;
        },
        show: function()
        {
            if (_openCal) {
                _closeDatePicker();
            }
            this.blur();
            var input = jQuery('input', jQuery(this).findClosestParent('input')[0])[0];
            
            _firstDate = input._startDate;
            _lastDate = input._endDate;
            _firstDayOfWeek = input._firstDayOfWeek;
            _openCal = jQuery(this).parent().find('>div.popup-calendar-wrapper');
            
            var d = jQuery(input).val();
            if (d != '') {
                if (_dateToStr(_strToDate(d)) == d) {
                    _selectedDate = d;
                    _draw(_getCalendarDiv(_strToDate(d)));
                } else {
                    // invalid date in the input field - just default to this month
                    _selectedDate = false;
                    _draw(_getCalendarDiv());
                }
            } else {
                _selectedDate = false;
                _draw(_getCalendarDiv());
            }
            /*
            if (jQuery.browser == "msie") {
                _openCal.bind('keypress', _handleKeys);
            } else {
                jQuery(window).bind('keypress', _handleKeys);
            }
            */
            jQuery(document).bind('mousedown', _checkMouse);
        },
        changeMonth: function(d, e)
        {
            _drawingMonth = true;
            _draw(_getCalendarDiv(d));
            _drawingMonth = false;
        },
        selectDate: function(d, ele)
        {
            selectedDate = d;
            var $theInput = jQuery('input', jQuery(ele).findClosestParent('input')[0]);
            $theInput.val(d);
            $theInput.trigger('change');
            _closeDatePicker(ele);
        },
        closeCalendar: function()
        {
            _closeDatePicker(this);
        },
        setInited: function(i)
        {
            i._inited = true;
        },
        isInited: function(i)
        {
            return i._inited != undefined;
        },
        setDateFormat: function(format,separator)
        {
            // set's the format that selected dates are returned in.
            // options are 'dmy' (european), 'mdy' (americian) and 'ymd' (unicode)
            dateFormat = format.toLowerCase();
            dateSeparator = separator?separator:"/";
        },
        /**
        * Function: setLanguageStrings
        *
        * Allows you to localise the calendar by passing in relevant text for the english strings in the plugin.
        *
        * Arguments:
        * days        -    Array, e.g. ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday']
        * months    -    Array, e.g. ['January', 'Febuary', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
        * navLinks    -    Object, e.g. {p:'Prev', n:'Next', c:'Close', b:'Choose date'}
        **/
        setLanguageStrings: function(aDays, aMonths, aNavLinks)
        {
            days = aDays;
            months = aMonths;
            navLinks = aNavLinks;
        },
        /**
        * Function: setDateWindow
        *
        * Used internally to set the start and end dates for a given date select
        *
        * Arguments:
        * i            -    The id of the INPUT element this date window is for
        * w            -    The date window - an object containing startDate and endDate properties
        *                each in the current format as set in a call to setDateFormat (or in the
        *                default format dmy if setDateFormat hasn't been called).
        *                e.g. {startDate:'01/03/2006', endDate:'11/04/2006}
        **/
        setDateWindow: function(i, w)
        {
            if (w == undefined) w = {};
            if (w.startDate == undefined) {
                i._startDate = new Date();
            } else {
                i._startDate = _strToDate(w.startDate);
            }
            if (w.endDate == undefined) {
                i._endDate = new Date();
                i._endDate.setFullYear(i._endDate.getFullYear()+5);
            } else {
                i._endDate = _strToDate(w.endDate);
            };
            i._firstDayOfWeek = w.firstDayOfWeek == undefined ? 0 : w.firstDayOfWeek;
        }
    };
}();
jQuery.fn.findClosestParent = function(s)
{
    var ele = this;
    while (true) {
        if (jQuery(s, ele[0]).length > 0) {
            return (ele);
        }
        ele = ele.parent();
        if(ele[0].length == 0) {
            return false;
        }
    }
};
jQuery.fn.datePicker = function(a)
{
    this.each(function() {
        if(this.nodeName.toLowerCase() != 'input') return;
        jQuery.datePicker.setDateWindow(this, a);
        if (!jQuery.datePicker.isInited(this)) {
            var chooseDate = jQuery.datePicker.getChooseDateStr();
            var calBut;
            if(a && a.inputClick){
                calBut = jQuery(this).attr('title', chooseDate).addClass('date-picker');
            }
            else {
                calBut = jQuery("<a></a>").attr({'href':'javascript:;',
'class':'date-picker', 'title':chooseDate})
                .append("<span>" + chooseDate + "</span>");
            }
            jQuery(this).wrap(
                '<div class="date-picker-holder"></div>'
            ).after(
                jQuery('<div></div>').attr('class', 'popup-calendar-wrapper').append(
                    jQuery("<div></div>").attr({'class':'popup-calendar'})
                ),
                calBut
            );
            calBut.bind('click', jQuery.datePicker.show);
            jQuery.datePicker.setInited(this);
        }
    });
    return this;
};